PSI - Issue 18

Yaroslav Dubyk et al. / Procedia Structural Integrity 18 (2019) 622–629 Yaroslav Dubyk and Iryna Seliverstova / Structural Integrity Procedia 00 (2019) 000–000

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4. Conclusions We developed a simple engineering approach for analysis of stress-strain state of dented pipelines using equivalent load method. On the basis of the general model of "harmonic" dent, we received an explicit analytical solution for a single dent. Comparison of analytical stresses with the results of numerical simulation shows the effectiveness of the proposed procedures. However, equivalent load method underestimates the peak stress concentrated value, it predicts quite good the stress profile. The peak stress value can be adjusted by a simple semi-analytical correction. Parametric calculations allow us the following conclusions to draw:  for small dents with increasing depth the stresses concentration increases and for small dents, this growth is more significant  the influence of pressure, for unproportional dent is more sagnificant then in case of axial force loading;  concentration due to the pressure load is more significant, and must be taken into account, especially for short dents, since it can exceed the nominal stress level by an excessive value.. EGIG. 2015. Gas Pipeline Incidents. 9th Report of the European Gas Pipeline Incident Data Group. Calladine, C. R., 1972. Structural Consequences of Small Imperfections in Elastic Thin Shells of Revolution. International Journal of Solids and Structures, 8, 679–697. Godoy, L. A., 1996., Thin-Walled Structures with Structural Imperfections. Tarrytown, NY: Pergamon. Li, C., Dang, C., 2017. Plastic damage analysis of oil and gas pipelines with unconstrained and constrained dents. Engineering Failure Analysis, 77, 39–49. Kec, J., Cerny, I., 2017. Stress-strain assessment of dents in wall of high pressure gas pipeline. Procedia Structural Integrity, 5, 340–346. Rinehart, A. J., Keating, P. B., 2007. Stress Concentration Solution for a 2D Dent in an Internally Pressurized Cylinder. Journal of Engineering Mechanics, 133(7), 792–800. Ying Wu,Y., Jiewen Xiao, J., Peng Zhang, P., 2016. The analysis of damage degree of oil and gas pipeline with type II plain dent. Engineering Failure Analysis, 66, 212–222. References